Conditional knockout mice lacking K(ATP) channel subunits

描述(申请人提供)：KATP通道是许多不同类型的细胞和组织的功能所必需的。然而，尽管这些通道在近25年前就被首次描述，但这些通道的生理和病理生理学作用现在才出现在大多数组织中。电生理和药理学方法使人们能够很好地了解KATP通道的作用。KATP通道(Kir6.1、Kir6.2、SUR1、SUR2A和/或SUR2B亚基)的分子鉴定进一步加深了我们对这些通道的分布和功能的了解。需要检验的压倒一切的假设是，生理和病理生理事件受制于存在于多个组织中的KATP通道的活性，不同组织类型的通道活动之间的同步相互作用决定了生理或病理生理结果的性质。传统的药理学方法不能在复杂的生物学环境中检验这一假说，因为这些化合物缺乏存在于不同组织类型中的不同类别的KATP通道所需的特异性。传统的KATP通道亚基基因敲除小鼠模型已经被开发出来，这些动物模型的出现极大地增加了我们对KATP通道在体内环境中功能的了解。然而，由于KATP通道亚单位在所有体细胞中的表达都被消除，因此在确定KATP通道亚单位在复杂的生物学环境(如缺血/再灌注)中的作用时，这些动物的使用带来了挑战。为了研究存在于多种组织中的KATP通道的相互作用以及它们在不同组织类型中的同步相互作用，需要新的工具来仅在特定的组织、细胞类型或亚细胞室中消除KATP通道。因此，该提议的目的是生成KATP通道亚基的每个条件敲除的四个小鼠模型。鉴于KATP通道的丰富多样性(就其组织分布和分子组成而言)，迫切需要产生缺乏每个KATP通道亚单位的条件性基因敲除小鼠。这些动物模型的发展将产生广泛的影响，不仅对我们自己的研究，而且对整个领域，因为这些作为这些研究的一部分产生的动物将允许研究人员在不同领域(心脏病学、内分泌学、神经学等)工作，以揭示KATP通道在健康和疾病中的组织特异性功能。与公众健康相关：ATP敏感的钾通道是独一无二的，因为它们将细胞内的能量代谢转化为细胞的活动和兴奋性，它们在许多不同类型的细胞的功能中发挥着非常重要的作用，它们有助于维持血糖水平，调节血流，参与神经递质的分泌，并防止缺血损伤。在生理和病理生理学背景下对KATP通道的研究出现了新的挑战，这些挑战不能使用现有的工具(即使是现有的常规基因敲除小鼠)来解决，这是我们提议建立新的基因改变的小鼠模型的基础，在该模型中，KATP通道亚单位可以在某些组织类型中特定地被删除。这些将被科学界广泛分享的小鼠，无疑将在许多研究领域(除了我们自己的研究之外)导致KATP通道研究的重大突破，这将对生物医学、行为和临床研究领域产生重大影响。

DESCRIPTION (provided by applicant): KATP channels are integral to the functions of many different types of cells and tissues. However, even though they were first described almost 25 years ago, the physiological and pathophysiological roles of these channels are only now emerging for most tissues. Electrophysiological and pharmacological methods have allowed for a good understanding of the roles of KATP channels. The molecular identification of KATP channels (Kir6.1, Kir6.2, SUR1, SUR2A and/or SUR2B subunits) has further advanced our knowledge regarding the distribution and function of these channels. The overriding hypothesis to be examined is that physiological and pathophysiological events are subject to the activity of KATP channels that are present in multiple tissues and that synchronous interaction between channel activities in diverse tissue types determines the nature of the physiological or pathophysiological outcome. Conventional pharmacological methods cannot be used to examine this hypothesis in a complex biological setting since these compounds lack required specificity for different classes of KATP channels present in diverse tissue types. Conventional knockout mouse models have been developed for each of the KATP channel subunits and the availability of these animal models has added significantly to our knowledge of the functions of KATP channels in the in-vivo setting. However, since the expression is eliminated in all somatic cells the use of these animals provides challenges when defining the roles of KATP channel subunits in complex biological settings (such as ischemia/reperfusion). To examine the interplay of KATP channels present in multiple tissues and their synchronous interaction in diverse tissue types, new tools are needed in which KATP channels are eliminated only in specific tissues, cell types or subcellular compartments. The purpose of this proposal is therefore to generate four mouse models of conditional knockouts of each of the KATP channel subunits. Given the rich diversity of KATP channels (both in terms to their tissue distribution and molecular composition), a dire need exists to generate conditional knockout mice devoid of each of the KATP channel subunits. The development of these animal models will have a wide ranging impact, not only on our own research, but also on the field in general since these animals generated as part of these studies will allow investigators working in diverse areas (cardiology, endocrinology, neurology, etc) to unravel the tissue specific functions of KATP channel in health and disease. PUBLIC HEALTH RELEVANCE: ATP-sensitive K+ channels are unique in that they transduce intracellular energy metabolism to cellular activity and excitability and they have very important roles on the functions of many different cell types and they help to maintain blood glucose levels, regulate blood flow, participate in the secretion of neurotransmitters and protect against ischemic insults. New challenges have arisen in the study of KATP channel in physiological and pathophysiological context that cannot be addressed using existing tools (even with the available conventional knockout mice), which is the rationale for our proposal to generate new genetically altered mouse models in which KATP channel subunits can be deleted specifically in certain tissue types. These mice, which will be widely shared with the scientific community, will undoubtedly lead to significant breakthroughs in the study of KATP channels in many study areas (in addition to our own research) and this will have a major impact on the fields of biomedical, behavioral and clinical research.